Under 2.8, we had no problems with this. Hotspot users with laptops could wander off, come back, and remain logged in.
Under 2.9, they seem to get logged out. The log message says something along the lines of "Hotspot user logged out; lost DHCP lease." I've tried setting the DHCP leases to long periods of time, and it doesn't seem to change things. Idle timeout is high, keepalive timeout is high...
It's not a HUGE problem, but it would be nice to not have laptops needing to re-login. Suggestions?